Built-up roof



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BUILT-UP ROOF Filed May 20, 1959 3 Sheets-Sheet 3 INVENTOR JAMES A.FIINAN BY 2W ATTORNEY United States Patent 3,053,715 BUILT-UP ROOF James A. Finan, Glenolden, Pa., assignor to Allied Chemical Corporation, New York, N.Y., a corporation of New York Filed May 20, 1959, Ser. No. 814,434 2 Claims. (Cl. 15451) This invention relates to built-up roofs and more particularly to a built-up roof constructed with laminated insulation boards having communicating moisture-conveying channels.

Roof insulation board is usually one-half inch thick. Greater thicknesses are obtained by laminating or bonding together two or more of the one-half inch boards, the one-half inch board typically containing about 4-5 percent water by weight and having a moisture equilibrium point at 50 percent relative humidity about 4.5-5.5 percent by weight. Laminating adhesives used for bonding the boards such as pearl starch and soybean paste adhesives generally contain from about 50-80 percent water. Consequently, when the porous boards are bonded together using such adhesives, the water content of the laminated board is increased locally from about 4-5 percent to about 9-10 percent by absorption. During installation of this laminated board of increased water content on the roof supporting structure, water evaporates from the upper surface of the board, particularly when the temperature of the roof deck is above 120 F., a common condition in summer sunny days. As the moisture is drawn up to the surface of the board and evaporates, the board lifts at the ends or warps. Such warping makes it difiicult and at times impossible to apply builtup roofing over the uneven surface.

Further, presence of air within the laminated insulation boards and the built-up roof may result in formation of roof blisters. When the roof is subjected to prolonged exposure to solar heat, the air within the insulation boards tends to expand greatly producing gas volumes and pressures which tend to produce undesirable blistering of the roof.

One object of this invention is to provide a built-up roof structure having improved discharge means for release of moisture from its thermal insulation layer.

Another object is to provide a built-up roof structure which eliminates buckling or warping of the roof insulation boards during and after installation.

Another object is to provide a built-up roof which will vent air pressures from the roof structure under conditions of prolonged exposure thereby reducing the likelihood of blistering of the roofing material.

Additional objects and advantages will be apparent as the invention is hereafter described in more detail.

In accordance with the present invention, the built-up roof structure comprises a supporting structure, a layer of thermal insulation comprising juxtaposed rigid porous laminated insulation boards on the supporting structure, the laminated boards each comprising bonded plies of porous fibrous insulation board having substantial moisture and gas absorptive characteristics, a plurality of spaced bands of adhesive material extending between and bonding adjacent plies together with the bands separating the plies to form moisture-air conveying channels between the spaced bands, the adhesive material of the bands being selected from the group consisting of soybean protein and starch adhesives and containing from about 50-80 percent of water when the plies are bonded whereby'the water content of the laminated boards is materially increased by absorption, each channel having height of about 0.03-0.06 inch as installed, the channels communicating with similar channels in adjoining laminated boards to permit the moisture to escape from the laminated boards during their installation and subsequent exposure at elevated roof deck temperature without material distortion and warping of the boards, and superposed layers of adhesive bituminous material and roofing felt overlying the layer of thermal insulation, the felt being bonded to the even outer surface of the insulation layer by the bituminous material. The communicating channels result in reduction of the water content of the laminated boards, enable moisture to escape without passing through the substantial entirety of the boards, and prevent substantial warping and distortion transmitted to the lower layers of the boards. Such reduction of the water or moisture content of the laminated boards by the communicating channels will continue on prolonged exposure of the roof to the atmosphere in the event water or moisture gains access to the interior of the laminated boards. Further the communicating channels considerably lessen or reduce the likelihood of blistering of superposed roofing material when subjected to solar heat by venting air pressures from the roof structure.

The built-up roof structure is constructed by preferably first superimposing a vapor barrier film of water vapor impervious material over the supporting structure. Such vapor barrier film is typically four mils thick and is formed of asphalt, pitch, polyethylene, aluminum, cellulose acetate, a plasticized polyvinyl chloride composition, polyester film or rubber like materials. The rigid laminated insulation boards having the moisture-air conveying channels and prepared as hereafter described are then laid over the vapor barrier film in juxtaposition to one another in manner such that the channels of the laminated board communicate wtih similar moisture-air conveying channels in adjoining laminated boards. Such boards have typical thickness of about 1 inch.

The spaced adhesive bands located between and bonding faces of adjacent plies of the laminated boards typically have widths of about 3-5 inches and heights of about 0.06-0.12 inch. The bands are spaced apart a minimum distance of 4 inches to about 8 inches whereby the channels have widths of from 4 to about 8 inches and heights of about 0.03-0.06 inch as installed. Such bands can be formed of suitable laminating adhesive materials or compositions well known in the art. Examples of such laminating adhesive compositions, which may contain a major amount, e.g. from about 50-80% water, are aqueous compositions containing, when applied to the board ply, by weight, (1) soybean meal-15.4%, lime-4.6% and water% and (2) pearl starch- 31.3%, diatomaceous earth-1.5% and water-67.2%.

The moisture-air conveying channels of the laid down insulation boards permit the absorbed moisture to escape from the boards at roof deck temperatures above F. without substantial warping or lifting of the boards at their ends. Consequently layers of adhesive bituminous material and roofing felt can be applied onto the outer surfaces of the laminated boards forming the insulation layer, which application was heretofore difficult and at times impossible due to the outer surfaces of the boards being uneven and warped caused 'by evaporation of water from the outer board surfaces.

Additionally the channels reduce the likelihood of blister ing of superposed roofing material by venting air pres sures from the roof structure. Such air pressures tend to be destructive if not released or vented from the insulating material, and are caused by expansion of oceluded air in the porous insulation material (due to solar heat) upon prolonged exposure of the roof to direct sunlight, such as during the summer months.

An adhesive layer of heat-liquefied bituminous material, e.g. asphalt or pitch is then applied to the outer surfaces of the laminated boards forming the insulation layer, the board outer surfaces being substantially even and non-warped. Thereafter a layer of bituminous material-saturated felt is applied or laid over the adhesive bituminous layer while the adhesive layer is in a soft and tacky condition, and the steps of applying the adhesive bituminous layer and then the bituminous material-saturated felt are repeated until a plurality of alternate superposed layers of the bituminous material and sat urated felt have been applied. Typically 4 layers of adhesive bituminous material and 3 layers of saturated felt are applied, although the number of layers applied may be varied as desired. Coarse mineral or aggregate particles, e.g. slag particles are preferably partially embedded in the surface of the outermost layer of hituminous material. The bituminous material layers typically each have thicknes of about 0.03-0.06 inch and the roofing felt layers typically each have thickness of about 0.06-0.l2 inch.

In the drawings:

FIG. 1 is a perspective view with parts broken away of a built-up roof of the present invention.

FIG. 2 is a section on line 22 of FIG.1.

FIG. 3 is a top plan view of laminated insulation hoards of the present invention laid in juxtaposition on a roof deck, the boards having communicating moistureconveying channels.

FIG. 4 is a top plan view of apparatus for preparation of the laminated insulation board of this invention.

FIG. 5 is an elevational section taken on line 5-5 of FIG. 4.

FIGS. 6 and 7 are enlarged detail views of the adhesive transfer or applicator roll and gauge roll respectively of the apparatus of FIG. 3.

With reference to FIGS. 1 and 2, a supporting structure or roof deck of wood, steel or concrete is designated at 10, and vapor barrier film 11 is superimposed on the roof deck. Laminated insulation board 12 comprises two plies 13 and 14 each of /2 inch thickness of porous cellulose fiber insulation board, the plies being bonded together by spaced approximately parallel bands 15, 16 and 17 of the soybean meal laminating adhesive composition previously disclosed.

Moisture-air conveying channels or passages 18 and 19, substantially rectangular shaped in cross section, are partially defined by and extend between adhesive bands or strips 15, 16 and 17, such channels communicating with similar moisture-air conveying channels 20 and 21 extending between substantially parallel bands 22, 23 and 24 in adjoining laminated insulation board 25. When the aqueous laminating adhesive composition is applied to the face of an insulation board ply in preparing the laminated board, the water or moisture content of the laminated board is increased from typically about 4-5% to about 9-10% by absorption. Such relatively high water content tends to be retained by the laminated boards prior to their installation when the boards are laminated at the plant or, if such is the case, at the job site. By reason of the communicating channels, the moisture escapes from the laminated boards during and after their installation at the elevated roof deck temperatures without causing substantial warping and distorting of the boards as discussed. The channels also vent air pressures from the roof structure which, if not vented, may cause roof blistering. Vent conduits provided with unidirectional check valves, e.g. tubular rubber exhalation or ball check valves, may be so disposed in the insulating structures as to communicate the intercommunicating channels with either the interior or exterior of the building thereby to complete escape or venting of the moisture and destructive pressures. Such unidirectional check valves are more fully described in US. Patents 2,833,229 and 2,849,018, issued May 6, 1958 and August 26, 1958, respectively.

Thin adhesive layers 27, 28 and 29 of coal-tar pitch bond waterproofing layers 30, 31 and 32 of tar-saturated felt respectively to the upper surface of laminated insulation board 12 and to one another. Outer layer 33 of coal-tar pitch has coarse particles 34 of slag partially embedded therein.

As shown in FIG. 3, laminated insulation boards 76, 77, 78, 79, 80, 81, 82 and 83 are juxtaposed to form a layer of thermal insulation on a roof deck. Each board has two edge bands and one central band of laminating adhesive of substantial height bonding together the two plies of the laminated board. Moisture-air conveying channels are located between the bands of each board and communicate with moisture-air conveying channels of adjoining laminated boards by reason of boards being laid end to end, for permitting moisture and also air pressures to escape from the boards. As shown, adhesive bands 84, and 86 of laminated board 77 have moisture conveying channels 87 and 88 therebetween. Channels 87 and 88 communicate with moisture air conveying channels 89 and and 91 and 92 respectively in adjoining laminated boards 78 and 76 by reason of boards 76, 77 and 78 being laid end to end. The moisture-air conveying channels of boards 78 and 76 and the other boards are located between adhesive bands (designated by the broken lines) similar to those of board 77.

Referring now to FIGS. 4 and 5, laminating adhesive material is applied to the upper surface of porous fibrous insulation board 35 in bands by passing board 35 beneath and in direct contact with rubber transfer or applicator roll 36. As shown in more detail in FIG. 6, transfer roll 36 has spaced raised surfaces 37, 38, 39, 40 and 41 and depressed or lowered surfaces 42, 43, 44, 45, 46 and 47 between the raised surfaces. Transfer roll 36 has steel gauge roll 48 closely adjacent thereto. As shown in more detail in FIG. 7, gauge roll 48 has spaced raised surfaces 50, 51, 52, 53, 54 and 55 and depressed surfaces 56, 57, 58, 59 and 60 which register with respectively the depressed surfaces and the raised surfaces of transfer roll 36. The raised surfaces of transfer roll 36 are grooved for retention of laminating adhesive until applied to board 35. Laminating adhesive material is pumped from a suitable source of supply to region 62 between gauge roll 48 and transfer roll 36, the distance between gauge roll 48 and and transfer roll 36 being adjusted to regulate the amount of adhesive deposited or applied on raised surfaces 37, 38, 39, 40 and 41 of the transfer roll. Rotating transfer roll 36 continuously deposits the adhesive material as spaced bands 63, 64, 65, 66 and 67 of substantial height on the surface of board 35, the raised surfaces of gauge roll 48 registering with the depressed surfaces of transfer roll and serving as wipers for the depressed surfaces to prevent appliction of adhesive to board ply 35 in the regions between the spaced bands.

Channels 69, 70, 71 and 72 are partially defined by and located between the spaced bands. Central adhesive band 65 is approximately twice as wide as adjacent bands 64 and 66, so that when board 35 is cut into boards of predetermined widths, the adhesive bands will be of approximately equal widths. The board with applied adhesive bands is then cut into two boards 73 and 74 of about equal widths by a saw (not shown). A second adhesivefree porous fiber insulation board of substantially identical dimensions as those of board 73 and 74 is then positioned or laid over each of board 73 and 74 in contact with the adhesive bands thereof, and maintained thereon for a typical assembly time of about 3 minutes. The resulting laminated boards are then ready for use in prepa ration of the built-up roof structure of this invention.

If desired to bond three board plies together to form a three ply laminated board, a second rubber transfer roll 36a similar to transfer roll 36 is used in the apparatus of FIGS. 4 and 5. This second transfer roll is located directly below transfer roll 36 and on the opposite side of insulation board 35 in contact with the board lower surface. Such second transfer roll also has a steel gauge roll 48a associated therewith similar to steel gauge roll 48,

and would operate and apply spaced adhesive bands to the lower surface of the board in manner and of dimensions similar to the bands applied to the board upper surface.

The insulation board can be fabricated of wood, bagasse, ground wood, chemical wood pulp, or flax straw fibers.

Cellulose fiber insulation boards were prepared each having 3 spaced bands of the aforementioned soybean meal adhesive composition extending lengthwise on one face thereof. Each band was of 3 inch width and 0.06 inch height and the bands were located at each edge of the board and at the center of the board extending lengthwise of the board, channels being provided between the bands. Each board had length of 48 inches, width of 24 inches and thickness of /2 inch. When boards of substantially identical dimensions were bonded to the boards having the spaced adhesive bands, generally rectangular shaped moisture-air conveying channels each of 7 inch width and 0.03 inch height were formed between the bands. Installation of such laminated insulation boards on a roof deck at roof deck temperatures above 120 F. results in no substantial warping and distorting of the laminated boards during the installation. Consequently, alternate layers of coal-tar pitch and roofing felt can be applied to the even, unwarped surface of the insulation layer, moisture normally causing warping of the boards at elevated roof deck temperature and air pressures being released from the boards through the channels.

Although certain preferred embodiments of the invention have been disclosed for purposes of illustration, it will be evident that various changes and modifications may be made therein without departing from the scope and spirit of the invention.

What is claimed is:

1. A built-up roof comprising a roof deck, a layer of thermal insulation comprising juxtaposed rigid porous laminated insulation boards on said roof deck, each laminated board comprising bonded plies of fibrous insulation board, a plurality of spaced continuous bands of adhesive material extending lengthwise between and bonding the adjacent plies together with the bands separating the plies to form moisture-air conveying channels between the spaced bands, each moisture-air conveying channel having height of about 0.030.06 inch as installed, said adhesive material of the bands being selected from the group consisting of soybean protein and starch adhesives and containing from about 0%80% of water when the plies are bonded whereby the water content of the laminated boards is materially increased by absorption, said channels communicating with similar moisture-air conveying channels in adjoining laminated boards for permitting the moisture to escape from the laminated boards during installation and subsequent exposure thereof on the roof deck without substantial warping of said boards and also air pressures from said boards, and superposed alternate layers of adhesive bituminous material and bituminous material-saturated felt overlying the thermal insulation layer, the lowermost felt layer being bonded to the outer surface of the insulation layer and the felt layers being bonded to one another by the adhesive bituminous material.

2. A built-up roof comprising a roof deck, a continuous film of water vapor impervious material superimposed on said roof deck, a layer of thermal insulation comprising juxtaposed rigid porous laminated insulation boards on said vapor impervious film, each laminated board comprising two bonded plies of cellulose fiber insulation board, a plurality of spaced continuous bands of adhesive material extending lengthwise between and bonding the plies together with the bands separating the plies to form moisture-air conveying channels between the spaced bands, each moisture-air conveying channel having height of about 0.030.06 inch as installed, said adhesive material of the bands being selected from the group consisting of soybean protein and pearl starch adhesives and containing from about 50%80% of water when the plies are bonded whereby the water content of the laminated boards is materially increased by absorption, said channels communicating with similar moisture-air conveying channels in adjoining laminated insulating boards for permitting the moisture to escape from the laminated boards during installation and subsequent exposure thereof on the roof deck without substantial warping of said boards and also air pressures from said boards, and superposed alternate layers of adhesive bituminous material and bituminous material-saturated felt overying the thermal insulation layer, the lowermost felt layer being bonded to the outer surface of the insulation layer and the felt layers being bonded to one another by the adhesive bituminous material.

References Cited in the file of this patent UNITED STATES PATENTS 1,931,066 Eckert Oct. 17, 1933 2,215,811 Figge Sept. 24, 1940 2,358,550 Williams Sept. 19, 1944 2,390,697 Eason Dec. 11, 1945 2,518,281 Camp et al Aug. 8, 1950 2,651,588 Bruce et a1. Sept. 8, 1953 2,833,229 Donegan May 6, 1958 2,849,018 Donegan et a1 Aug. 26, 1958 2,932,589 Meyer et a1 Apr. 12, 1960 FOREIGN PATENTS 269,730 Switzerland 1950 

2. A BUILT-UP ROOF COMPRISING A ROOF DECK, A CONTINUOUS FILM OF WATER VAPOR IMPERVIOUS MATERIAL SUPERIMPOSED ON SAID ROOF DECK, A LAYER OF THERMAL INSULATION COMPRISING JUXTAPOSED RIGID POROUS LAMINATED INSULATION BOARDS IN SAID VAPOR IMPERVIOUS FILM, EACH LAMINATED BOARD COMPRISING TWO BONDED PILES OF CELLULOSE FIBER INSULATION BOARD, A PLURALITY OF SPACED CONTINUOUS BANDS OF ADHESIVE MATERIAL EXTENDING LENGTHWISE BETWEEN AND BONDING THE PLIES TOGETHER WITH THE BANDS SEPARATING THE PLIES TO FORM MOISTURE-AIR CONVEYING CHANNELS BETWEEN THE SPACED BANDS, EACH MOISTURE-AIR CONVEYING CHANNEL HAVING HEIGHT OF ABOUT 0.03-0.006 INCH AS INSTALLED, SAID ADHESIVE MATERIAL OF THE BANDS BEING SELECTED FROM THE GROUP CONSISTING OF SOYBEAN PROTEIN AND PEARL STARCH ADHESIVES AND CONTAINING FROM ABOUT 50%-80% OF WATER WHEN THE PLIES ARE BONDED WHEREBY THE WATER CONTENT OF THE LAMINATED BOARDS IS MATERIALLY INCREASED BY ABSORPTION, SAID CHANNELS COMMUNICATING WITH SIMILAR MOISTURE-AIR CONVEYING CHANNELS IN ADJOINING LAMINATED INSULATING BOARDS FOR PERMITTING THE MOISTURE TO ESCAPE FROM THE LAMINATED BOARDS DURING INSTALLATION AND SUBSEQUENT EXPOSURE THEREOF ON THE ROOF DECK WITHOUT SUBSTANTIAL WARPING OF SAID BOARDS AND ALSO AIR PRESSURES FROM SAID BOARDS, AND SUPERPOSED ALTERNATE LAYERS OF ADHESIVE BITUMINOUS MATERIAL AND BITUMINOUS MATERIAL-SATURATED FELT OVERYING THE THERMAL INSULATION LAYER, THE LOWERMOST FELT LAYER BEING BONDED TO THE OUTER SURFACE OF THE INSULATION LAYER AND THE FELT LAYERS BEING BONDED TO ONE ANOTHER BY THE ADHESIVE BITUMINOUS MATERIAL. 